The number of carry-on bags passing through security checkpoints has surged since airlines began charging customers for checking luggage. Travelers carried on 59 million more bags in 2010 than the previous year, according to the Transportation Security Administration. TSA Administrator John Pistole said the increase in bags has created more work for the TSA. "One is the sheer volume of the bags, the carry-on bags. But then two, most are fairly densely packed because people are trying to get everything in," he said. Some observers say the surge in bags increases the likelihood that the TSA will fail to detect weapons.